Estrogenic potential of Di-isobutyl phthalate (DIBP) and Di-isononyl phthalate (DINP) was studied using two different test systems. Two different doses of DIBP (250 and 1250 mg/kg) and DINP (276 and 1380 mg/kg) were administered to immature female rats (20 days old) orally once daily for 3 and 20 days in uterotrophic and pubertal assay, respectively. The animals were sacrificed on day 4 and day 41 in case of 3-day uterotrophic and 20-day pubertal assay, respectively. The results indicated that non-significant alterations in uterine and ovarian wet weight were observed in both the DIBP- and DINP-treated groups while the uterus weight increased significantly (i.e., 4–6 times) in the Diethylstilbesterol (DES)-treated group in both the assays. In the present study, precocious vaginal opening occurred at 26 days of age in the DES-treated group with a mean body weight of 30.39 ± 1.08 g. However, no precocious vaginal opening was found in any of the DIBP- and DINP-treated groups. The results indicated that both the phthalate compounds were unable to induce elevation in the uterine weight in both the assays and unable to cause vaginal opening indicating non-estrogenic potential of both the phthalate compounds, i.e., DIBP and DINP in vivo.

An analytical methodology using automatic thermal desorption and gas chromatography mass spectrometry analysis was optimized and validated for simultaneous determination of a set of components from three different flame retardant chemical classes: polybrominated diphenyl ethers (PBDEs) (PBDE-28, PBDE-47, PBDE-66, PBDE-85, PBDE-99, PBDE-100), organophosphate flame retardants (PFRs) (tributyl phosphate, tripropyl phosphate, tris(2-chloroethyl)phosphate-, tris(1,3-dichloro-2-propyl) phosphate, tris(2-ethylhexyl) phosphate, triphenyl phosphate, tris(2-chloro-1-methylethyl) phosphate and tricresylphosphate), and “novel” brominated flame retardants (NBFRs) (pentabromotoluene, 2,3,4,5,6-pentabromoethylbenzene, (2,3-dibromopropyl) (2,4,6-tribromophenyl) ether, hexabromobenzene, and 2-ethylhexyl 2,3,4,5-tetrabromobenzoate) in air. The methodology is based on low volume active air sampling of gaseous and particulate air fractions on mixed-bed (polydimethylsiloxane (PDMS)/Tenax TA) sorption tubes. The optimized method provides recoveries >88 %; a limit of detection in the range of 6–25 pg m⁻³ for PBDEs, 6–171 pg m⁻³ for PFRs, and 7–41 pg m⁻³ for NBFRs; a linearity greater than 0.996; and a repeatability of less than 10 % for all studied compounds. The optimized method was compared with a standard method using active air sampling on XAD-2 sorbent material, followed by liquid extraction. On the one hand, the PDMS/Tenax TA method shows comparable results at longer sampling time conditions (e.g., indoor air sampling, personal air sampling). On the other hand, at shorter sampling time conditions (e.g., sampling from emission test chambers), the optimized method detects up to three times higher concentrations and identifies more flame retardant compounds compared to the standard method based on XAD-2 loading.

The present study investigates the phenolic profile of exudates and extracts of the green algae Dunaliella tertiolecta, harvested in natural seawater in the absence (control) and in the presence of Cu(II) (315 and 790 nmol L⁻¹) and Fe(III) (900 nmol L⁻¹) in order to identify and quantify the phenolic compounds produced under metallic stress conditions. The presence of metal ions modifies the growth of cells and changes cell metabolism by producing phenolic compounds adapted to the solution. The use of reversed-phase high-performance liquid chromatography (RP-HPLC) permitted the identification of 14 phenolic constituents. The concentration and type of polyphenols detected in cell extracts and in solution are directly related with the metal and its concentration during growth cultures, achieving 1.4 times higher levels of polyphenols under 790 nmol Cu(II) L⁻¹ with respect to the control experiments. Microalga excretes polyphenols to be adapted to the environmental conditions. Gentisic acid, (+) catechin and (−) epicatechin, the most prominent phenolic compounds detected in the algae extracts, showed high antioxidant activity in inhibiting 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. This potent activity may be related to its presence in cells and exudates in high concentrations.

We investigated the ozonation of the antineoplastic drugs cyclophosphamide (CP), ifosfamide (IF), and 5-fluorouracil (5-FU) and of the vasodilator pentoxifylline (PEN) in distilled water, in pharmaceutical wastewater, and in hospital effluent at pH 5–11. Under an alkaline pH of 11, all of the target compounds rapidly degraded through the attack of hydroxyl radicals, which resulted in their complete removal within 5 min at an ozone supply rate of 3 g O₃/h. Under acidic pH conditions, such as pH 5.6, CP and IF exhibited slower removal rates; however, compounds with unsaturated C-C bonds, such as 5-FU and PEN, were still removed at rapid rates under acidic conditions. Although the parent compounds were removed within minutes, the resulting ozonation byproducts were resistant to further ozonation and possessed increased Microtox acute toxicity. In distilled water, the resulting ozonation products exhibited minimal mineralization but high acute toxicity, whereas in naturally buffered pharmaceutical and hospital effluents, the byproducts were more amenable to removal and detoxification.

A mixed sulfur–iron particles packed reactor (SFe reactor) was developed to simultaneously remove total nitrogen (TN) and total phosphorus (TP) of the secondary effluent from municipal wastewater treatment plants. Low effluent TN (<1.5 mg/L) and TP (<0.3 mg/L) concentrations were simultaneously obtained, and high TN removal rate [1.03 g N/(L·d)] and TP removal rate [0.29 g P/(L·d)] were achieved at the hydraulic retention time (HRT) of 0.13 h. Kinetic models describing denitrification were experimentally obtained, which predicted a higher denitrification rate [1.98 g N/(L·d)] of SFe reactor than that [1.58 g N/(L·d)] of sulfur alone packed reactor due to the mutual enhancement between sulfur-based autotrophic denitrification and iron-based chemical denitrification. A high TP removal obtained in SFe reactor was attributed to chemical precipitation of iron particles. Microbial community analysis based on 16S rRNA revealed that autotrophic denitrifying bacteria Thiobacillus and Sulfuricella were the dominant genus, indicating that autotrophic denitrification played important role in nitrate removal. These results indicate that sulfur and iron particles can be packed together in a single reactor to effectively remove nitrate and phosphorus.

The present research investigated to what extent results obtained in small microcosm experiments can be extrapolated to larger settings with non-uniform concentrations. Microbial hydrocarbon degradation in sandy sediments was compared for column experiments versus homogenized microcosms with varying concentrations of diesel, Syntroleum, and fish biodiesel as contaminants. Syntroleum and fish biodiesel had higher degradation rates than diesel fuel. Microcosms showed significantly higher overall hydrocarbon mineralization percentages (p < 0.006) than columns. Oxygen levels and moisture content were likely not responsible for that difference, which could, however, be explained by a strong gradient of fuel and nutrient concentrations through the column. The mineralization percentage in the columns was similar to small-scale microcosms at high fuel concentrations. While absolute hydrocarbon degradation increased, mineralization percentages decreased with increasing fuel concentration which was corroborated by saturation kinetics; the absolute CO₂ production reached a steady plateau value at high substrate concentrations. Numerical modeling using HYDRUS 2D/3D simulated the transport and degradation of the investigated fuels in vadose zone conditions similar to those in laboratory column experiments. The numerical model was used to evaluate the impact of different degradation rate constants from microcosm versus column experiments.

The objective of the study was to estimate how water treatment (stimulation of real conditions) by H₂O₂ and/or UV affects carbon nanotube (CNT) properties and fate (stability/aggregation) in water and tannic acid solution. The processes studied had only a slight effect on SBET, porosity, and surface composition of CNTs. There was a change in the morphology of CNTs. After H₂O₂ and/or UV treatment, CNTs underwent shortening, opening up of their ends, and exfoliation. Treatment with H₂O₂ increased the content of oxygen in CNTs. A decrease was observed in the surface charge and in the mobility of CNTs, which caused an increase in their stability. UV irradiation of CNTs led to an increased incidence of defects that were manifested by both an increase of zeta potential and an increased mobility of CNT, whereas the presence of H₂O₂ during UV irradiation had only a slight effect on the parameters of the porous structure of nanotubes.

China is one of the largest producers, consumers, and traders for pesticides in the world. Currently, there are more than 600 pesticide-active substances registered in China, whereas few studies were conducted to improve our understanding of the occurrence and environmental impact of current-use pesticides (CUPs) in China’s environment. In this work, 72 surface sediment samples were taken from the coastal and offshore of Bohai and Yellow seas and were analyzed for six CUPs (trifluralin, dacthal, quintozene, endosulfan, chlorpyrifos, and dicofol) and two metabolites (pentachloroanisole and endosulfan sulfate). Sediment samples were categorized as estuarine or near-shore sediments (Laizhou Bay, Taozi Bay, Sishili Bay, and Jiaozhou Bay) and offshore sediments. Trifluralin, α-endosulfan, endosulfan sulfate, chlorpyrifos, dicofol, and pentachloroanisole were detected in more than 60 % of the samples. Dicofol was the predominant compound with concentrations mostly higher than 100 pg/g dry weight (dw) with the highest concentration of 18,000 pg/g dw. Concentrations of other compounds were mainly below 100 pg/g dw. CUP levels were much lower than the sediment screening benchmark calculated. The highest levels of α-endosulfan, endosulfan sulfate, trifluralin, and chlorpyrifos existed at Laizhou Bay, whereas pentachloroanisole and dicofol had highest mean concentrations at Jiaozhou Bay. Generally, no correlation between pesticide concentrations and total organic carbon was observed either for offshore samples or for near-shore samples.

The potential sources of tritium input to the Yenisei River ecosystem are derived from local operations of nuclear facilities of the Mining and Chemical Combine operated by the state-owned Rosatom corporation and from sources derived from global weapons testing fallout and nuclear power. The background tritium concentrations in zoobenthos, bottom sediments, relevant commercial fish species, and widespread endogenous aquatic plants have been obtained for the first time in this region. Our results demonstrate that the major input term of tritium to this region of the Yenisei is derived from nearby mining operations of Rosatom, with tritium concentrations in aquatic plants marginally exceeding the observed background values obtained from upstream control sample collection sites.

Thermal treatments are the primary technologies used to remove persistent organic pollutants from contaminated solids. The high energy consumption during continuous heating, required cost for treating the exhaust gas, and potential formation of secondary pollutants during combustion have prevented their implementation. A novel successive self-propagated sintering process was proposed for removing polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) from contaminated solids in a low-cost and environmentally friendly way. Nine laboratory-scale experiments involving different initial concentrations of pollutants and solid compositions were performed. Almost all PCBs (>99 %) and HCB (>97 %) were removed from solids under constant experimental conditions. Varying initial concentrations of PCBs and HCB in the contaminated solids did not influence the removal efficiency of the pollutants; however, the degradation efficiency of pollutants increased as their initial concentrations increased. Although varying levels of PCDD/Fs were detected in the effluent gas, they were all within the emission standard limit.